Sodium peroxide which is a yellow solid, when exposed to air becomes white due to the formation of

• H₂O₂

• NaOH and Na₂CO₃

• Na₂O

• NaOH and H₂O₂

The carbonate that will not decompose on heating is

• Na₂CO₃

• CaCO₃

• BaCO₃

• SrCO₃

Thomas slag is referred to as :

• calcium silicate

• calcium phosphate

• barium phosphate

• strontium silicate

Which one of the following statements is true for all the alkali metals?

• They react with halogens to give the halides MX

• Their nitrates decompose on heating to give NO₂ and O₂

• Their carbonates decompose on heating to give CO₂ and the metal oxide

• They react with oxygen to give mainly the oxide MO2

Alkali metals have high oxidation potential and hence, they behave as :

• oxidizing agents

• Lewis bases

• reducing agents

• electrolytes

The effective component, of bleaching powder............is the of calcium :

• Cl^-

• OCl^-

• O^2-

• O₂Cl^-

In the lime kiln, the reaction CaCO₃(s) → CaO(s) + CO₂ (g) goes to completion because:

• of high temperature

• CaO is more stable than CaCO₃

• CO₂ escapes simultaneously

• CO₂ is a gaseous product

48.

CaCl₂ is used as

• disinfectant

• desiccating agent

• medicine

• None of these

Dry distillation of calcium acetate and calcium formate forms:

• methanol

• ethanal

• ethanol

• acetone

With cold and dilute sodium hydroxide fluorine reacts to give

• NaF and OF₂

• NaF + O₃

• O₂ and O₃

• NaF + O₂